// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// This file contains an implementation of a VP8 raw stream parser,
// as defined in RFC 6386.

#include "base/logging.h"
#include "media/filters/vp8_parser.h"

namespace media {

#define ERROR_RETURN(what)                               \
    do {                                                 \
        DVLOG(1) << "Error while trying to read " #what; \
        return false;                                    \
    } while (0)

#define BD_READ_BOOL_OR_RETURN(out) \
    do {                            \
        if (!bd_.ReadBool(out))     \
            ERROR_RETURN(out);      \
    } while (0)

#define BD_READ_BOOL_WITH_PROB_OR_RETURN(out, prob) \
    do {                                            \
        if (!bd_.ReadBool(out, prob))               \
            ERROR_RETURN(out);                      \
    } while (0)

#define BD_READ_UNSIGNED_OR_RETURN(num_bits, out) \
    do {                                          \
        int _out;                                 \
        if (!bd_.ReadLiteral(num_bits, &_out))    \
            ERROR_RETURN(out);                    \
        *out = _out;                              \
    } while (0)

#define BD_READ_SIGNED_OR_RETURN(num_bits, out)        \
    do {                                               \
        int _out;                                      \
        if (!bd_.ReadLiteralWithSign(num_bits, &_out)) \
            ERROR_RETURN(out);                         \
        *out = _out;                                   \
    } while (0)

Vp8FrameHeader::Vp8FrameHeader()
{
    memset(this, 0, sizeof(*this));
}

Vp8Parser::Vp8Parser()
    : stream_(nullptr)
    , bytes_left_(0)
{
}

Vp8Parser::~Vp8Parser()
{
}

bool Vp8Parser::ParseFrame(const uint8_t* ptr,
    size_t frame_size,
    Vp8FrameHeader* fhdr)
{
    stream_ = ptr;
    bytes_left_ = frame_size;

    memset(fhdr, 0, sizeof(*fhdr));
    fhdr->data = stream_;
    fhdr->frame_size = bytes_left_;

    if (!ParseFrameTag(fhdr))
        return false;

    fhdr->first_part_offset = stream_ - fhdr->data;

    if (!ParseFrameHeader(fhdr))
        return false;

    if (!ParsePartitions(fhdr))
        return false;

    DVLOG(4) << "Frame parsed, start: " << static_cast<const void*>(ptr)
             << ", size: " << frame_size
             << ", offsets: to first_part=" << fhdr->first_part_offset
             << ", to macroblock data (in bits)=" << fhdr->macroblock_bit_offset;

    return true;
}

static inline uint32_t GetBitsAt(uint32_t data, size_t shift, size_t num_bits)
{
    return ((data >> shift) & ((1 << num_bits) - 1));
}

bool Vp8Parser::ParseFrameTag(Vp8FrameHeader* fhdr)
{
    const size_t kFrameTagSize = 3;
    if (bytes_left_ < kFrameTagSize)
        return false;

    uint32_t frame_tag = (stream_[2] << 16) | (stream_[1] << 8) | stream_[0];
    fhdr->key_frame = static_cast<Vp8FrameHeader::FrameType>(GetBitsAt(frame_tag, 0, 1));
    fhdr->version = GetBitsAt(frame_tag, 1, 2);
    fhdr->is_experimental = !!GetBitsAt(frame_tag, 3, 1);
    fhdr->show_frame = !!GetBitsAt(frame_tag, 4, 1);
    fhdr->first_part_size = GetBitsAt(frame_tag, 5, 19);

    stream_ += kFrameTagSize;
    bytes_left_ -= kFrameTagSize;

    if (fhdr->IsKeyframe()) {
        const size_t kKeyframeTagSize = 7;
        if (bytes_left_ < kKeyframeTagSize)
            return false;

        static const uint8_t kVp8StartCode[] = { 0x9d, 0x01, 0x2a };
        if (memcmp(stream_, kVp8StartCode, sizeof(kVp8StartCode)) != 0)
            return false;

        stream_ += sizeof(kVp8StartCode);
        bytes_left_ -= sizeof(kVp8StartCode);

        uint16_t data = (stream_[1] << 8) | stream_[0];
        fhdr->width = data & 0x3fff;
        fhdr->horizontal_scale = data >> 14;

        data = (stream_[3] << 8) | stream_[2];
        fhdr->height = data & 0x3fff;
        fhdr->vertical_scale = data >> 14;

        stream_ += 4;
        bytes_left_ -= 4;
    }

    return true;
}

bool Vp8Parser::ParseFrameHeader(Vp8FrameHeader* fhdr)
{
    if (!bd_.Initialize(stream_, bytes_left_))
        return false;

    bool keyframe = fhdr->IsKeyframe();
    if (keyframe) {
        unsigned int data;
        BD_READ_UNSIGNED_OR_RETURN(1, &data); // color_space
        BD_READ_UNSIGNED_OR_RETURN(1, &data); // clamping_type
    }

    if (!ParseSegmentationHeader(keyframe))
        return false;

    fhdr->segmentation_hdr = curr_segmentation_hdr_;

    if (!ParseLoopFilterHeader(keyframe))
        return false;

    fhdr->loopfilter_hdr = curr_loopfilter_hdr_;

    int log2_nbr_of_dct_partitions;
    BD_READ_UNSIGNED_OR_RETURN(2, &log2_nbr_of_dct_partitions);
    fhdr->num_of_dct_partitions = static_cast<size_t>(1)
        << log2_nbr_of_dct_partitions;

    if (!ParseQuantizationHeader(&fhdr->quantization_hdr))
        return false;

    if (keyframe) {
        BD_READ_BOOL_OR_RETURN(&fhdr->refresh_entropy_probs);
    } else {
        BD_READ_BOOL_OR_RETURN(&fhdr->refresh_golden_frame);
        BD_READ_BOOL_OR_RETURN(&fhdr->refresh_alternate_frame);

        int refresh_mode;
        if (!fhdr->refresh_golden_frame) {
            BD_READ_UNSIGNED_OR_RETURN(2, &refresh_mode);
            fhdr->copy_buffer_to_golden = static_cast<Vp8FrameHeader::GoldenRefreshMode>(refresh_mode);
        }

        if (!fhdr->refresh_alternate_frame) {
            BD_READ_UNSIGNED_OR_RETURN(2, &refresh_mode);
            fhdr->copy_buffer_to_alternate = static_cast<Vp8FrameHeader::AltRefreshMode>(refresh_mode);
        }

        BD_READ_UNSIGNED_OR_RETURN(1, &fhdr->sign_bias_golden);
        BD_READ_UNSIGNED_OR_RETURN(1, &fhdr->sign_bias_alternate);
        BD_READ_BOOL_OR_RETURN(&fhdr->refresh_entropy_probs);
        BD_READ_BOOL_OR_RETURN(&fhdr->refresh_last);
    }

    if (keyframe)
        ResetProbs();

    fhdr->entropy_hdr = curr_entropy_hdr_;

    if (!ParseTokenProbs(&fhdr->entropy_hdr, fhdr->refresh_entropy_probs))
        return false;

    BD_READ_BOOL_OR_RETURN(&fhdr->mb_no_skip_coeff);
    if (fhdr->mb_no_skip_coeff)
        BD_READ_UNSIGNED_OR_RETURN(8, &fhdr->prob_skip_false);

    if (!keyframe) {
        BD_READ_UNSIGNED_OR_RETURN(8, &fhdr->prob_intra);
        BD_READ_UNSIGNED_OR_RETURN(8, &fhdr->prob_last);
        BD_READ_UNSIGNED_OR_RETURN(8, &fhdr->prob_gf);
    }

    if (!ParseIntraProbs(&fhdr->entropy_hdr, fhdr->refresh_entropy_probs,
            keyframe))
        return false;

    if (!keyframe) {
        if (!ParseMVProbs(&fhdr->entropy_hdr, fhdr->refresh_entropy_probs))
            return false;
    }

    fhdr->macroblock_bit_offset = bd_.BitOffset();
    fhdr->bool_dec_range = bd_.GetRange();
    fhdr->bool_dec_value = bd_.GetBottom();
    fhdr->bool_dec_count = 7 - (bd_.BitOffset() + 7) % 8;

    return true;
}

bool Vp8Parser::ParseSegmentationHeader(bool keyframe)
{
    Vp8SegmentationHeader* shdr = &curr_segmentation_hdr_;

    if (keyframe)
        memset(shdr, 0, sizeof(*shdr));

    BD_READ_BOOL_OR_RETURN(&shdr->segmentation_enabled);
    if (!shdr->segmentation_enabled)
        return true;

    BD_READ_BOOL_OR_RETURN(&shdr->update_mb_segmentation_map);
    BD_READ_BOOL_OR_RETURN(&shdr->update_segment_feature_data);
    if (shdr->update_segment_feature_data) {
        int mode;
        BD_READ_UNSIGNED_OR_RETURN(1, &mode);
        shdr->segment_feature_mode = static_cast<Vp8SegmentationHeader::SegmentFeatureMode>(mode);

        for (size_t i = 0; i < kMaxMBSegments; ++i) {
            bool quantizer_update;
            BD_READ_BOOL_OR_RETURN(&quantizer_update);
            if (quantizer_update)
                BD_READ_SIGNED_OR_RETURN(7, &shdr->quantizer_update_value[i]);
            else
                shdr->quantizer_update_value[i] = 0;
        }

        for (size_t i = 0; i < kMaxMBSegments; ++i) {
            bool loop_filter_update;
            BD_READ_BOOL_OR_RETURN(&loop_filter_update);
            if (loop_filter_update)
                BD_READ_SIGNED_OR_RETURN(6, &shdr->lf_update_value[i]);
            else
                shdr->lf_update_value[i] = 0;
        }
    }

    if (shdr->update_mb_segmentation_map) {
        for (size_t i = 0; i < kNumMBFeatureTreeProbs; ++i) {
            bool segment_prob_update;
            BD_READ_BOOL_OR_RETURN(&segment_prob_update);
            if (segment_prob_update)
                BD_READ_UNSIGNED_OR_RETURN(8, &shdr->segment_prob[i]);
            else
                shdr->segment_prob[i] = Vp8SegmentationHeader::kDefaultSegmentProb;
        }
    }

    return true;
}

bool Vp8Parser::ParseLoopFilterHeader(bool keyframe)
{
    Vp8LoopFilterHeader* lfhdr = &curr_loopfilter_hdr_;

    if (keyframe)
        memset(lfhdr, 0, sizeof(*lfhdr));

    int type;
    BD_READ_UNSIGNED_OR_RETURN(1, &type);
    lfhdr->type = static_cast<Vp8LoopFilterHeader::Type>(type);
    BD_READ_UNSIGNED_OR_RETURN(6, &lfhdr->level);
    BD_READ_UNSIGNED_OR_RETURN(3, &lfhdr->sharpness_level);
    BD_READ_BOOL_OR_RETURN(&lfhdr->loop_filter_adj_enable);

    if (lfhdr->loop_filter_adj_enable) {
        BD_READ_BOOL_OR_RETURN(&lfhdr->mode_ref_lf_delta_update);
        if (lfhdr->mode_ref_lf_delta_update) {
            for (size_t i = 0; i < kNumBlockContexts; ++i) {
                bool ref_frame_delta_update_flag;
                BD_READ_BOOL_OR_RETURN(&ref_frame_delta_update_flag);
                if (ref_frame_delta_update_flag)
                    BD_READ_SIGNED_OR_RETURN(6, &lfhdr->ref_frame_delta[i]);
            }

            for (size_t i = 0; i < kNumBlockContexts; ++i) {
                bool mb_mode_delta_update_flag;
                BD_READ_BOOL_OR_RETURN(&mb_mode_delta_update_flag);
                if (mb_mode_delta_update_flag)
                    BD_READ_SIGNED_OR_RETURN(6, &lfhdr->mb_mode_delta[i]);
            }
        }
    }

    return true;
}

bool Vp8Parser::ParseQuantizationHeader(Vp8QuantizationHeader* qhdr)
{
    // If any of the delta values is not present, the delta should be zero.
    memset(qhdr, 0, sizeof(*qhdr));

    BD_READ_UNSIGNED_OR_RETURN(7, &qhdr->y_ac_qi);

    bool delta_present;

    BD_READ_BOOL_OR_RETURN(&delta_present);
    if (delta_present)
        BD_READ_SIGNED_OR_RETURN(4, &qhdr->y_dc_delta);

    BD_READ_BOOL_OR_RETURN(&delta_present);
    if (delta_present)
        BD_READ_SIGNED_OR_RETURN(4, &qhdr->y2_dc_delta);

    BD_READ_BOOL_OR_RETURN(&delta_present);
    if (delta_present)
        BD_READ_SIGNED_OR_RETURN(4, &qhdr->y2_ac_delta);

    BD_READ_BOOL_OR_RETURN(&delta_present);
    if (delta_present)
        BD_READ_SIGNED_OR_RETURN(4, &qhdr->uv_dc_delta);

    BD_READ_BOOL_OR_RETURN(&delta_present);
    if (delta_present)
        BD_READ_SIGNED_OR_RETURN(4, &qhdr->uv_ac_delta);

    return true;
}

// See spec for details on these values.
const uint8_t kCoeffUpdateProbs[kNumBlockTypes][kNumCoeffBands]
                               [kNumPrevCoeffContexts][kNumEntropyNodes]
    = {
          {
              {
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 176, 246, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 223, 241, 252, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 249, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 244, 252, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 234, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 246, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 239, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 251, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 251, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 254, 253, 255, 254, 255, 255, 255, 255, 255, 255 },
                  { 250, 255, 254, 255, 254, 255, 255, 255, 255, 255, 255 },
                  { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
          },
          {
              {
                  { 217, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 225, 252, 241, 253, 255, 255, 254, 255, 255, 255, 255 },
                  { 234, 250, 241, 250, 253, 255, 253, 254, 255, 255, 255 },
              },
              {
                  { 255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 223, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 238, 253, 254, 254, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 249, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 253, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 247, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 252, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
          },
          {
              {
                  { 186, 251, 250, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 234, 251, 244, 254, 255, 255, 255, 255, 255, 255, 255 },
                  { 251, 251, 243, 253, 254, 255, 254, 255, 255, 255, 255 },
              },
              {
                  { 255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 236, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 251, 253, 253, 254, 254, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 254, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 254, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
          },
          {
              {
                  { 248, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 250, 254, 252, 254, 255, 255, 255, 255, 255, 255, 255 },
                  { 248, 254, 249, 253, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 246, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 252, 254, 251, 254, 254, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 254, 252, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 248, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 253, 255, 254, 254, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 245, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 253, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 251, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 252, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 252, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 249, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 255, 253, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
              {
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
                  { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
              },
          },
      };

const uint8_t kKeyframeYModeProbs[kNumYModeProbs] = { 145, 156, 163, 128 };
const uint8_t kKeyframeUVModeProbs[kNumUVModeProbs] = { 142, 114, 183 };

const uint8_t kDefaultYModeProbs[kNumYModeProbs] = { 112, 86, 140, 37 };
const uint8_t kDefaultUVModeProbs[kNumUVModeProbs] = { 162, 101, 204 };

const uint8_t kDefaultCoeffProbs[kNumBlockTypes][kNumCoeffBands]
                                [kNumPrevCoeffContexts][kNumEntropyNodes]
    = {
          { {
                { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
                { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
                { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
            },
              {
                  { 253, 136, 254, 255, 228, 219, 128, 128, 128, 128, 128 },
                  { 189, 129, 242, 255, 227, 213, 255, 219, 128, 128, 128 },
                  { 106, 126, 227, 252, 214, 209, 255, 255, 128, 128, 128 },
              },
              {
                  { 1, 98, 248, 255, 236, 226, 255, 255, 128, 128, 128 },
                  { 181, 133, 238, 254, 221, 234, 255, 154, 128, 128, 128 },
                  { 78, 134, 202, 247, 198, 180, 255, 219, 128, 128, 128 },
              },
              {
                  { 1, 185, 249, 255, 243, 255, 128, 128, 128, 128, 128 },
                  { 184, 150, 247, 255, 236, 224, 128, 128, 128, 128, 128 },
                  { 77, 110, 216, 255, 236, 230, 128, 128, 128, 128, 128 },
              },
              {
                  { 1, 101, 251, 255, 241, 255, 128, 128, 128, 128, 128 },
                  { 170, 139, 241, 252, 236, 209, 255, 255, 128, 128, 128 },
                  { 37, 116, 196, 243, 228, 255, 255, 255, 128, 128, 128 },
              },
              {
                  { 1, 204, 254, 255, 245, 255, 128, 128, 128, 128, 128 },
                  { 207, 160, 250, 255, 238, 128, 128, 128, 128, 128, 128 },
                  { 102, 103, 231, 255, 211, 171, 128, 128, 128, 128, 128 },
              },
              {
                  { 1, 152, 252, 255, 240, 255, 128, 128, 128, 128, 128 },
                  { 177, 135, 243, 255, 234, 225, 128, 128, 128, 128, 128 },
                  { 80, 129, 211, 255, 194, 224, 128, 128, 128, 128, 128 },
              },
              {
                  { 1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
                  { 246, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
                  { 255, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
              } },
          { {
                { 198, 35, 237, 223, 193, 187, 162, 160, 145, 155, 62 },
                { 131, 45, 198, 221, 172, 176, 220, 157, 252, 221, 1 },
                { 68, 47, 146, 208, 149, 167, 221, 162, 255, 223, 128 },
            },
              {
                  { 1, 149, 241, 255, 221, 224, 255, 255, 128, 128, 128 },
                  { 184, 141, 234, 253, 222, 220, 255, 199, 128, 128, 128 },
                  { 81, 99, 181, 242, 176, 190, 249, 202, 255, 255, 128 },
              },
              {
                  { 1, 129, 232, 253, 214, 197, 242, 196, 255, 255, 128 },
                  { 99, 121, 210, 250, 201, 198, 255, 202, 128, 128, 128 },
                  { 23, 91, 163, 242, 170, 187, 247, 210, 255, 255, 128 },
              },
              {
                  { 1, 200, 246, 255, 234, 255, 128, 128, 128, 128, 128 },
                  { 109, 178, 241, 255, 231, 245, 255, 255, 128, 128, 128 },
                  { 44, 130, 201, 253, 205, 192, 255, 255, 128, 128, 128 },
              },
              {
                  { 1, 132, 239, 251, 219, 209, 255, 165, 128, 128, 128 },
                  { 94, 136, 225, 251, 218, 190, 255, 255, 128, 128, 128 },
                  { 22, 100, 174, 245, 186, 161, 255, 199, 128, 128, 128 },
              },
              {
                  { 1, 182, 249, 255, 232, 235, 128, 128, 128, 128, 128 },
                  { 124, 143, 241, 255, 227, 234, 128, 128, 128, 128, 128 },
                  { 35, 77, 181, 251, 193, 211, 255, 205, 128, 128, 128 },
              },
              {
                  { 1, 157, 247, 255, 236, 231, 255, 255, 128, 128, 128 },
                  { 121, 141, 235, 255, 225, 227, 255, 255, 128, 128, 128 },
                  { 45, 99, 188, 251, 195, 217, 255, 224, 128, 128, 128 },
              },
              {
                  { 1, 1, 251, 255, 213, 255, 128, 128, 128, 128, 128 },
                  { 203, 1, 248, 255, 255, 128, 128, 128, 128, 128, 128 },
                  { 137, 1, 177, 255, 224, 255, 128, 128, 128, 128, 128 },
              } },
          { {
                { 253, 9, 248, 251, 207, 208, 255, 192, 128, 128, 128 },
                { 175, 13, 224, 243, 193, 185, 249, 198, 255, 255, 128 },
                { 73, 17, 171, 221, 161, 179, 236, 167, 255, 234, 128 },
            },
              {
                  { 1, 95, 247, 253, 212, 183, 255, 255, 128, 128, 128 },
                  { 239, 90, 244, 250, 211, 209, 255, 255, 128, 128, 128 },
                  { 155, 77, 195, 248, 188, 195, 255, 255, 128, 128, 128 },
              },
              {
                  { 1, 24, 239, 251, 218, 219, 255, 205, 128, 128, 128 },
                  { 201, 51, 219, 255, 196, 186, 128, 128, 128, 128, 128 },
                  { 69, 46, 190, 239, 201, 218, 255, 228, 128, 128, 128 },
              },
              {
                  { 1, 191, 251, 255, 255, 128, 128, 128, 128, 128, 128 },
                  { 223, 165, 249, 255, 213, 255, 128, 128, 128, 128, 128 },
                  { 141, 124, 248, 255, 255, 128, 128, 128, 128, 128, 128 },
              },
              {
                  { 1, 16, 248, 255, 255, 128, 128, 128, 128, 128, 128 },
                  { 190, 36, 230, 255, 236, 255, 128, 128, 128, 128, 128 },
                  { 149, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
              },
              {
                  { 1, 226, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
                  { 247, 192, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
                  { 240, 128, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
              },
              {
                  { 1, 134, 252, 255, 255, 128, 128, 128, 128, 128, 128 },
                  { 213, 62, 250, 255, 255, 128, 128, 128, 128, 128, 128 },
                  { 55, 93, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
              },
              {
                  { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
                  { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
                  { 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128 },
              } },
          {
              {
                  { 202, 24, 213, 235, 186, 191, 220, 160, 240, 175, 255 },
                  { 126, 38, 182, 232, 169, 184, 228, 174, 255, 187, 128 },
                  { 61, 46, 138, 219, 151, 178, 240, 170, 255, 216, 128 },
              },
              {
                  { 1, 112, 230, 250, 199, 191, 247, 159, 255, 255, 128 },
                  { 166, 109, 228, 252, 211, 215, 255, 174, 128, 128, 128 },
                  { 39, 77, 162, 232, 172, 180, 245, 178, 255, 255, 128 },
              },
              {
                  { 1, 52, 220, 246, 198, 199, 249, 220, 255, 255, 128 },
                  { 124, 74, 191, 243, 183, 193, 250, 221, 255, 255, 128 },
                  { 24, 71, 130, 219, 154, 170, 243, 182, 255, 255, 128 },
              },
              { { 1, 182, 225, 249, 219, 240, 255, 224, 128, 128, 128 },
                  { 149, 150, 226, 252, 216, 205, 255, 171, 128, 128, 128 },
                  { 28, 108, 170, 242, 183, 194, 254, 223, 255, 255, 128 } },
              {
                  { 1, 81, 230, 252, 204, 203, 255, 192, 128, 128, 128 },
                  { 123, 102, 209, 247, 188, 196, 255, 233, 128, 128, 128 },
                  { 20, 95, 153, 243, 164, 173, 255, 203, 128, 128, 128 },
              },
              {
                  { 1, 222, 248, 255, 216, 213, 128, 128, 128, 128, 128 },
                  { 168, 175, 246, 252, 235, 205, 255, 255, 128, 128, 128 },
                  { 47, 116, 215, 255, 211, 212, 255, 255, 128, 128, 128 },
              },
              {
                  { 1, 121, 236, 253, 212, 214, 255, 255, 128, 128, 128 },
                  { 141, 84, 213, 252, 201, 202, 255, 219, 128, 128, 128 },
                  { 42, 80, 160, 240, 162, 185, 255, 205, 128, 128, 128 },
              },
              {
                  { 1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
                  { 244, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
                  { 238, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128 },
              },
          },
      };

const uint8_t kMVUpdateProbs[kNumMVContexts][kNumMVProbs] = {
    {
        237,
        246,
        253,
        253,
        254,
        254,
        254,
        254,
        254,
        254,
        254,
        254,
        254,
        254,
        250,
        250,
        252,
        254,
        254,
    },
    {
        231,
        243,
        245,
        253,
        254,
        254,
        254,
        254,
        254,
        254,
        254,
        254,
        254,
        254,
        251,
        251,
        254,
        254,
        254,
    },
};

const uint8_t kDefaultMVProbs[kNumMVContexts][kNumMVProbs] = {
    {
        162,
        128,
        225,
        146,
        172,
        147,
        214,
        39,
        156,
        128,
        129,
        132,
        75,
        145,
        178,
        206,
        239,
        254,
        254,
    },
    {
        164,
        128,
        204,
        170,
        119,
        235,
        140,
        230,
        228,
        128,
        130,
        130,
        74,
        148,
        180,
        203,
        236,
        254,
        254,
    },
};

void Vp8Parser::ResetProbs()
{
    static_assert(
        sizeof(curr_entropy_hdr_.coeff_probs) == sizeof(kDefaultCoeffProbs),
        "coeff_probs_arrays_must_be_of_correct_size");
    memcpy(curr_entropy_hdr_.coeff_probs, kDefaultCoeffProbs,
        sizeof(curr_entropy_hdr_.coeff_probs));

    static_assert(sizeof(curr_entropy_hdr_.mv_probs) == sizeof(kDefaultMVProbs),
        "mv_probs_arrays_must_be_of_correct_size");
    memcpy(curr_entropy_hdr_.mv_probs, kDefaultMVProbs,
        sizeof(curr_entropy_hdr_.mv_probs));

    static_assert(
        sizeof(curr_entropy_hdr_.y_mode_probs) == sizeof(kDefaultYModeProbs),
        "y_probs_arrays_must_be_of_correct_size");
    memcpy(curr_entropy_hdr_.y_mode_probs, kDefaultYModeProbs,
        sizeof(curr_entropy_hdr_.y_mode_probs));

    static_assert(
        sizeof(curr_entropy_hdr_.uv_mode_probs) == sizeof(kDefaultUVModeProbs),
        "uv_probs_arrays_must_be_of_correct_size");
    memcpy(curr_entropy_hdr_.uv_mode_probs, kDefaultUVModeProbs,
        sizeof(curr_entropy_hdr_.uv_mode_probs));
}

bool Vp8Parser::ParseTokenProbs(Vp8EntropyHeader* ehdr,
    bool update_curr_probs)
{
    for (size_t i = 0; i < kNumBlockTypes; ++i) {
        for (size_t j = 0; j < kNumCoeffBands; ++j) {
            for (size_t k = 0; k < kNumPrevCoeffContexts; ++k) {
                for (size_t l = 0; l < kNumEntropyNodes; ++l) {
                    bool coeff_prob_update_flag;
                    BD_READ_BOOL_WITH_PROB_OR_RETURN(&coeff_prob_update_flag,
                        kCoeffUpdateProbs[i][j][k][l]);
                    if (coeff_prob_update_flag)
                        BD_READ_UNSIGNED_OR_RETURN(8, &ehdr->coeff_probs[i][j][k][l]);
                }
            }
        }
    }

    if (update_curr_probs) {
        memcpy(curr_entropy_hdr_.coeff_probs, ehdr->coeff_probs,
            sizeof(curr_entropy_hdr_.coeff_probs));
    }

    return true;
}

bool Vp8Parser::ParseIntraProbs(Vp8EntropyHeader* ehdr,
    bool update_curr_probs,
    bool keyframe)
{
    if (keyframe) {
        static_assert(
            sizeof(ehdr->y_mode_probs) == sizeof(kKeyframeYModeProbs),
            "y_probs_arrays_must_be_of_correct_size");
        memcpy(ehdr->y_mode_probs, kKeyframeYModeProbs,
            sizeof(ehdr->y_mode_probs));

        static_assert(
            sizeof(ehdr->uv_mode_probs) == sizeof(kKeyframeUVModeProbs),
            "uv_probs_arrays_must_be_of_correct_size");
        memcpy(ehdr->uv_mode_probs, kKeyframeUVModeProbs,
            sizeof(ehdr->uv_mode_probs));
    } else {
        bool intra_16x16_prob_update_flag;
        BD_READ_BOOL_OR_RETURN(&intra_16x16_prob_update_flag);
        if (intra_16x16_prob_update_flag) {
            for (size_t i = 0; i < kNumYModeProbs; ++i)
                BD_READ_UNSIGNED_OR_RETURN(8, &ehdr->y_mode_probs[i]);

            if (update_curr_probs) {
                memcpy(curr_entropy_hdr_.y_mode_probs, ehdr->y_mode_probs,
                    sizeof(curr_entropy_hdr_.y_mode_probs));
            }
        }

        bool intra_chroma_prob_update_flag;
        BD_READ_BOOL_OR_RETURN(&intra_chroma_prob_update_flag);
        if (intra_chroma_prob_update_flag) {
            for (size_t i = 0; i < kNumUVModeProbs; ++i)
                BD_READ_UNSIGNED_OR_RETURN(8, &ehdr->uv_mode_probs[i]);

            if (update_curr_probs) {
                memcpy(curr_entropy_hdr_.uv_mode_probs, ehdr->uv_mode_probs,
                    sizeof(curr_entropy_hdr_.uv_mode_probs));
            }
        }
    }

    return true;
}

bool Vp8Parser::ParseMVProbs(Vp8EntropyHeader* ehdr, bool update_curr_probs)
{
    for (size_t mv_ctx = 0; mv_ctx < kNumMVContexts; ++mv_ctx) {
        for (size_t p = 0; p < kNumMVProbs; ++p) {
            bool mv_prob_update_flag;
            BD_READ_BOOL_WITH_PROB_OR_RETURN(&mv_prob_update_flag,
                kMVUpdateProbs[mv_ctx][p]);
            if (mv_prob_update_flag) {
                uint8_t prob;
                BD_READ_UNSIGNED_OR_RETURN(7, &prob);
                ehdr->mv_probs[mv_ctx][p] = prob ? (prob << 1) : 1;
            }
        }
    }

    if (update_curr_probs) {
        memcpy(curr_entropy_hdr_.mv_probs, ehdr->mv_probs,
            sizeof(curr_entropy_hdr_.mv_probs));
    }

    return true;
}

bool Vp8Parser::ParsePartitions(Vp8FrameHeader* fhdr)
{
    CHECK_GE(fhdr->num_of_dct_partitions, 1u);
    CHECK_LE(fhdr->num_of_dct_partitions, kMaxDCTPartitions);

    // DCT partitions start after the first partition and partition size values
    // that follow it. There are num_of_dct_partitions - 1 sizes stored in the
    // stream after the first partition, each 3 bytes long. The size of last
    // DCT partition is not stored in the stream, but is instead calculated by
    // taking the remainder of the frame size after the penultimate DCT partition.
    size_t first_dct_pos = fhdr->first_part_offset + fhdr->first_part_size + (fhdr->num_of_dct_partitions - 1) * 3;

    // Make sure we have enough data for the first partition and partition sizes.
    if (fhdr->frame_size < first_dct_pos)
        return false;

    // Total size of all DCT partitions.
    size_t bytes_left = fhdr->frame_size - first_dct_pos;

    // Position ourselves at the beginning of partition size values.
    const uint8_t* ptr = fhdr->data + fhdr->first_part_offset + fhdr->first_part_size;

    // Read sizes from the stream (if present).
    for (size_t i = 0; i < fhdr->num_of_dct_partitions - 1; ++i) {
        fhdr->dct_partition_sizes[i] = (ptr[2] << 16) | (ptr[1] << 8) | ptr[0];

        // Make sure we have enough data in the stream for ith partition and
        // subtract its size from total.
        if (bytes_left < fhdr->dct_partition_sizes[i])
            return false;

        bytes_left -= fhdr->dct_partition_sizes[i];

        // Move to the position of the next partition size value.
        ptr += 3;
    }

    // The remainder of the data belongs to the last DCT partition.
    fhdr->dct_partition_sizes[fhdr->num_of_dct_partitions - 1] = bytes_left;

    DVLOG(4) << "Control part size: " << fhdr->first_part_size;
    for (size_t i = 0; i < fhdr->num_of_dct_partitions; ++i)
        DVLOG(4) << "DCT part " << i << " size: " << fhdr->dct_partition_sizes[i];

    return true;
}

} // namespace media
